Temperature indicator means for sadirons



y 31, 1949- c. H.- ISPARKLIN 71,458

TEMPERATURE INDICATOR MEANS FOR SADIRONS Filed May 15, 1944 2 Sheets-Sheet l y 1949. c. H. SPARKLIN 2,471,458

TEMPERATURE INDICATOR MEANS FOR SADIRONS Filed May 15, 1944 2 Sheets-Sheet 2 Patented May 31, 1949 TEMPERATURES mnrca'roa MEANS FOR ADIRONS Charles 11. Sparklin, Chicago, n1, assignor to Birtman Electric Company, a corporation of Illinois Application May 15, 1944, Serial No. 535,646

This inventionrelates to a sadiron or flatiron and more particularly to a thermostatic control or indicator therefor.

The invention is illustrated in the drawings in which Figure 1 is a side elevation of the iron; Figure 2'is a plan view thereof; Figure 3 is a sectional plan view; Figure 4 is a vertical section taken along the line 4-4 in Figure 3; Figure 5 is a horizontal section taken along the line' 5-5 in Figure 4; and Figure 6 is an enlarged sectional elevation taken along the line 6-6 in Figure 3.

The iron comprises a sole plate lllhaving a hood II, a handle l2 and a hand rest l3. A resistance element I5 is embedded in the base, preferably as described in my co-pending application Serial No. 524,850, filed March 3, 1944 now abandoned. Suitable electrical connections (not shown) are incorporated in the resistance element.

The iron is provided with an automatic thermostaticsnap control of conventional form comprising the bimetallic strip I6 secured to the sole plate; a leaf spring strip l1 having a contact extension |8 carried by the bimetal; and the spring member |9 having a stud 2|] contacting the stud 2| on the strip H.

The automatic thermostat may be adjusted for various operating conditions of the iron by the stop 25 which is mounted on the arm 26 pivoted at 2I. The arm forms a yoke 28 at its forward end, and this yoke is carried in the groove 29 of the collar 30 which is threaded on the post 3|. A square sleeve 32 is carried by the post 3| above the collar 30 and is free to rotate upon the post.

The upper end of the post 3| is anchored in the knob 33 which is likewise secured to the sleeve 32 so that, on rotation of the knob, both sleeve and post turn with it.

The gear 35 has a square central opening slightly larger than the sleeve and is slidably mounted on thel sleeve between the strap 36 and the hoodl 3 Claims. (Cl. 73-343) pending application, Serial No. 535,645, filed May 15, 1944, which matured OnDecember 28, 1948 into Patent No. 2,457,185, has a number of advantages in that it permits remote control of an indicator which may be arranged in a part of the iron convenient to the eye, whereas the control' is set in a part of the iron convenient to the fingers. In addition it also permits the combination of a setting-indicating means with a temperature indicator so that the operator can I tell at one glance whether the temperature of the iron corresponds to the desired setting.

Such a temperature indicator '50 is here provided upon the same shaft 5| which carries the setting indicator 40. The temperature indicator comprises a segmental curved arm 52 hearing the appropriate temperature indications 53, 54 and 55. For example, portion 53 may be painted in red, section 54 in yellow, and 55 in green. The indicator is calibrated so that whenever the red portion of the temperature indicator underlies the setting indicator 40, the iron will be too hot for the indicated conditions. Conversely, when the green portion underlies the setting indicator,

the iron will be too cold for the indicated conditions. When the yellow portion underlies the setting indicator, the iron will be at the proper operating temperature.

The present device provides a means by which the customary flat bimetal strip may be attached to the sole plate with a face thereof in contact with the upper face of the plate so as to provide vertical deflection of the bimetal, but to convert this motion into horizontal travel of the The gear 35 is connected through a gear train 7 temperature indicator.

In the present form of such device the bimetal strip is secured to the upper surface of the sole plate at 6| with its lower face adjacent the horizontal upper face of the sole plate. The outer end of the bimetal is bent at an angle of 90 to form the vertical end portion 62. This is provided with a lost motion connection to a crank arm 63, for example, by means of a pin and slot engagement. This is illustrated by pin 64 carried by the arm 63 and a slot 65 in the end portion 62. The arm 63 which is pivoted at 66 has an extension 61 carrying a ball 68 at its upper end. This ball is mounted in the slot 10 of the yoke 69. The yoke is carried by the arm ll pivoted at 12. The arm has a gear extension 13 engaging the ring gear 14 on the shaft 5|.

It will be observed that as the iron heats up.

motion of the pin e4 within the 5101; es. Upward motion of the crank 83 moves the extension arm 01 to the right, as shown in Figure 6, and movement of the ball 88 to the right, as shown in- Figure 3, moves the yoke 09 in the same direction, moving the gear extension 13 in the opposite direction, and the ring gear 14 in a clockwise direction. As a result. the temperature indicator 50 moves in a clockwise direction, as viewed in Figure 3, as the temperature of the iron rises. It will be observed that ,the transverse component of the radial "motion of the yoke 09 is compensated by lost motion of the ball 58 within the slot 10, and that the vertical component of the radial'motion of the arm 61 is compensated by vertical lost motion of the ball within the slot.

Twisting of the bimetal 80 provides sumcient rigidity to produce the necessary motive force.

The foregoing detailed description has been given for cleamessof understanding only, and no unnecessary limitations should be understood 4 therefrom.

WhatI claim as new, and desire to secure by Letters Patent, is:

1. In -a temperature indicator for a sadiron having a sole plate, a temperature-responsive fiat strip having one end thereof afllxed to the upper surface of the sole plate and arranged flat against said sole plate, said strip extending at an acute angle from the sole plate with the other end of said strip being twisted approximately 90, a bracket mounted on the sole plate adjacent the twisted end of said strip, a bell crank having a pair of arms and mounted on the bracket for rotation about a horizontal axis that is located adjacent the base of said arms, one arm of said bell crank slidably eng ing said upwardly extending end of said strip and the other arm of the bell crank extending generally upwardly, a gear sector operably connected to said upwardly extending arm of the bell crank, and indicating means operably connected to and actuated by said gear sector. 1

2. Elements of a temperature indicator as set forth in claim 1, in which the twisted end of said strip is provided with a longitudinal slot, and the corresponding end of the bell crank is provided with a pin enga ing said slot.

3. Elements of a temperature indicator as set 4 forth in claim 1, in which the upwardly-extending end of the bell crank is provided, with a ball element extending upwardly from the bell crank and engaging a slot in the gear sector.

CHARIESESPARKL} REFERENCES CITED The following references are of record in the tile 01' this patent:

v UNITED STATES PATENTS Number Samuels July 16, 1940 

